Compressor lubricating device



May 23, 1939. J. c. McCUNE COMPRESSOR LUBRICATING DEVICE Filed March 27, 1937 INVENTOR JQSEPH C. MCCUNE. 9M

ATTORNEY wk kn R wk 3 S sh Patented May 23, 1939 UNITED STATES oommmssoawnmoa'rmo DEVICE Joseph C. McCune, Edgewood, Pa., assig'nor to The 3 Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application March 27, 1937, Serial No. 133,368

3 Claims.

This invention relates to a fluid compressor and particularly to improved means to maintain the supply of lubricant in the compressor lubricating system.

As usually constructed fluid compressors have crankcase chambers adapted to hold a quantity of lubricant. In some types of compressors the capacity of the crankcase chamber is relatively small, and the chamber will not hold sumcient lubricant to permit the compressor to be operated for extended periods of time without the addition of lubricant to replace that consumed during operation of the compressor.

It is an object of this invention to provide a 15 supplementary lubricant reservoir adapted for use with a compressor, together with means for automatically supplying lubricant from this reservoir to the compressor crankcase chamber to maintain the lubricant in the compressor crankcase chamber substantially at a predetermined level.

A further object of the invention is to provide a supplementary lubricant source, together with means responsive to an operating condition of a fluid compressor for supplying lubricant from this source to the crankcase chamber of the compressor.

Another object of the invention is to provide a supplementary lubricant reservoir adapted to be employed with a fluid compressor, and automatic means for supplying lubricant from this reservoir to the crankcase chamber of the compressor, to-

gether with means to return lubricant from the crankcase chamber to the reservoir in the event of an oversupply of lubricant to the compressor crankcase chamber.

A further object of the invention is to provide lubricant supply means adapted to be employed with a fluid compressor having associated therewith unloading means and a control device responsive to an operating condition of the compressor for controlling the unloading means, the

lubricant supply means having means controlled by the control device for supplying lubricant from a supplementary lubricant source to the compressor crankcase chamber.

Another object of the invention is to provide an improved compressor lubricating system.

A further object of the invention is to provide a lubricant supply means adapted to be em. ployed with a fluid compressor of the type having a crankcase chamber adapted to contain a quantity of lubricant, the lubricant supply means comprising a reservoir adapted to contain a :5 quantity of lubricant and automatic means for supplying lubricant from this reservoir to the compressor crankcase chamber to maintain the level of the lubricant in the crankcase chamber substantially at a predetermined level.

Another object of the invention is to provide lubricant supply means for a compressor of the type having a pressure lubricating system, the supply means comprising a supplementary lubricant reservoir andmeans responsive to the pressure of the lubricant inthe compressor lubricating system for supplying lubricant from the reservoir to the compressor crankcase chamber.

Other objects of the invention and featuresof novelty will be apparent from the following description taken in connection with the accompanying drawing, in which Fig. 1 is a diagrammatic view, largely in section, of a fluid compressor equipped with the improved lubricating system provided by this invention, and

Fig-2 is an enlarged sectional view taken substantially along the line 22 of Fig. 1.

Referring to the drawing there is illustrated in Fig. 1 a fluid compressor I which may be of any suitable well known construction. This compressor comprises a body having a bore therein in which is mounted a piston 2 having a compression chamber 4 at the upper face thereof. The body of the compressor I has a crankcase chamber 5 formed therein, while a crankshaft l for reciprocating the piston 2 is-mounted in this chamber. The crankcase chamber 5 is adapted to hold a quantity of lubricant to lubricate the operating portions of the compressor, w hile lubricant is supplied to the crankcase chamber through a suitable filler opening, not shown.

The crankcase chamber 5 is substantially sealed, and is connected to the atmosphere through a passage in a plug 8, while this passage is controlled by means of a ball check valve 9 which operates to permit fluid to escape from the crank case chamber 5 to the atmosphere and to prevent flow of fluid from the atmosphere to the crank case chamber.

The compressor I has associated therewith a lubricant pump in for supplying lubricant under pressure to portions of the compressor. This pump is mounted in the crank case chamber 5 and comprises a body l2 which is pivotally supported by brackets I4 and I5, which are secured to the bottom wall of the crank case chamber. The body I2 has a bore therein in which is reciprocable a plunger I6 which is mounted on an eccentric l8 formed on the crankshaft I. The plunger l6 has a passage l9 extending therethrough and communicating with an annular groove 20' in the face of the eccentric Ill. The groove 20 is connected by means of a passage 2| with a groove in the face of the bearing surface on the crankshaft on which is mounted the connecting rod 6 for reciprocating the piston 2,

The passage H! has a choke 22 interposed therein, while a ball chack valve 24 is yieldingly pressed by a spring 25 against a seat surrounding the end of the passage Hi to permit lubricant toflowfromtheboreinthebody I2.tothep'assage I8. and to prevent back flow of lubricant fromthe eI8.

At one point in its range of movement the end of the plunger I8 is located above a passage 21. which leads from the lower portion of the crankcase chamber 5 to the bore in the body i2, to permit lubricant to flow from the crank casechambertotheboreinthebody I2,while at another point in its range of movement the plunger l8 cuts 01! communication through this A e 28 communicates with the bore in the body I2 at a point adjacent the end thereof, and communicates through a choke 28 with a pipe 88 leading to a control device associated with the compressor. A pressure release device 82 is provided to control the pressure of the lubricant in the e 28. This device comprises a ball valve 88 which is normally held in the seated position by a spring 84 to prevent the release of lubricant from the w e 28. while this valve isimseatedonapredeterminedincreaseinthe pressure of the lubricant in the passage 28.to release lubricant therefrom and thus reduce the pressure therein. 1

The compressor I has a removable cylinder head 88 in which is formed an exhaust chamber 88 which is constantly connected with a reservoir 48 by way of a pipe 4|. The exhaust chamber 88 has mounted therein an exhaust valve assembly 42 which may be of any well hiown con struction. and operates to permit fluid to flow from the compression chamber 4 to the exhaust chamber 88 and thence to the reservoir 48, and to prevent back flow of fluid from the reservoir 48 and the exhaust chamber 88 to the compression chamber 4.

The head 88 of the compressor I alsohas formed therein an inlet chamber. 44 which is constantly connected to the atmosphere by way of a passage 45, while an inlet valve assembly 48 is mounted in this chamber. As shown the inlet valve as sembly 48 comprises a seat member 41 having an annular seat rib formed thereon which is adapted to be engaged by a disc valve 48. The valve 48 is yieldingly pressed into engagement with the seat member 41 by a coil spring 48 which extends between the valve 48 and a spring cage 58.

A pipe 48 is provided and connects the crank case chamber 5 with a passage in the cylinder head 88 which is open to the inlet passage 45.

The inlet valve assembly 48 has associated therewith unloading means indicated generally by the reference numeral 52. The unloading means 52 comprises a body 54 which is secured in the cylinder head 38 and serves to maintain the seat member 41 in position in the inlet chamber I4. The body 54 has a bore therein in which is mounted a plunger 58 having a stem 51 which is adapted to engage the valve 48 to move the valve away from its seat on the seat member 41. A coil spring 58 is mounted in the bore in the body 54 and yieldingly urges the plunger 58 up- 'wardly so that the end of the stem 51 is spaced from the valve 48, thereby permitting the spring 48 to hold the valve 48 in engagement with the seat member 41.

The upper end of the plunger 58 engages one face of a flexible diaphragm 88 which is clamped between the body 54 and a cap member 8i. The diaphragm 88 has at the other face thereof a chamber 82 which is connected by way of a pipe 84 with a control device indicated generally with the reference numeral 88.

The unloading control device 88 may be of any suitable well known construction and the device employed with the compressor shown in this application is shown and clainied in U. 8. Patent No. 2,065,204, to Burton 5. Altman. This device comprises a flexible diaphragm 18 which is clamped between the body sections 1i and 12 and has at one face a chamber 14 which is constantly connected by way of a e and pipe with the reservoir 48. The other face of the diaphragm 18 is engaged by a plunger 11 having a stem. on which is mounted a coil spring 18 and a plate 18. The spring 18 extends between the Plate 18 and an adjustable spring seat 88, while movement of the plunger and the diaphragm by the spring is limited by engagement of the plate 18 with the face of the body section 12.

The control device 88 includes a body section 18 having a bore therein in which is mounted a disc valve 82 and a plunger 88. The valve 82 is yieldingly pressed against the seat rib 84 by means of a coil spring 88 operating through the plunger 88. The area within the seat rib 84 is open to a chamber 88 formed by the body sections 12 and 18, while this chamber and the chamber 88 at the spring side of the plunger 88 are connected by way of a passage 88 with a bore in the body section 12, and thence by way of a passage and pipe 88 to the crankcase chamber 5 of the compressor 1.

The body section 12 has a bore therein in which is mounted a piston 82 having at one face thereof a chamber 88 to which is connected a branch of the passage 88 to which is connected the pipe 88 leading from the compressor lubricant pump I8, while another branch of the passage 88 communicates with the chamber 85 in the body section 18 between the disc valve 82 and the plunger 83.

The body section 12 also has a chamber 84 therein to which is connected the pipe 84 leadin to the compressor unloading means 52, and in which is mounted a double beat valve 85. This valve has a fluted stem mounted in a bore which is supplied with fluid under pressure from the passage 15, which is connected to the reservoir 48, while the valve 85 has a seating face thereon adapted to engage a seat surrounding this bore to cut oil. the supply of fluid under pressure from the passage 15 to the chamber 84 and thence to the pipe 84 leading to the compressor unloading means 52. V

The valve 85 also has a fluted stem mounted in a bore extending between the chamber'84 and the chamber 88 at the face of the piston 82, which chamber is open to the atmosphere through the passage and pipe 88 and the compressor crankcase chamber 5. The valve 85 is yieldingly urged to the right, as viewed in the drawing, by a coil spring 81, while an end of the stem of the valve is engaged by the piston 82 so that the piston may move the valve against the spring 81.

In operation, assuming that fluid under pressure is present in the reservoir 48 at a value less than a predetermined value, and that the compressor I is idle so that no pressure is exerted by the pump II on the lubricant in the compressor lubricating system, the spring 81 holds the valve 85 in the pofltion to prevent the release of fluid from the chamber 84 to the chamber 88, and to permit the supply of fluid from the passage 15 to the chamber 84 and thence by way of the pipe 84 to the chamber 82 of the compressor unloading means 52. Fluid under pressure in the chamber 82 exerts force through the diaphragm 88 to hold the plunger 58 against the spring 58 so that the end of the stem of the plunger 58 holds the inlet valve 48 against the spring 49 awayfrom its seat to thereby unload the compressor.

Upon rotation of the compressor crankshaft I the piston 2is reciprocated, and on the downward strokes of the piston fluid from the atmosphere is drawn into the compression chamber 4 through the inlet passage 45, while this fluid is forced out from the compression chamber 4 to the atmosphere past the open inlet valve 48 on the upward strokes of the piston 2.

Upon rotation of the crankshaft l the plunger I 6 of the lubricant pump I9 is reciprocated in the bore in the body I 2, and on its upward strokes causes lubricant to be drawn into this bore from the crankcase chamber 5 through the passage 21, and on its downward strokes the plunger i6 subjects this lubricant to pressure so that lubricant flows past the ball check valve 24 to the passage i9, and thence to the groove 29 in the eccentric I8, from which lubricant flows through the passage 2i in the crank shaft 1 to the bearing for the connecting rod 6.

Lubricant under pressure is also supplied to the passage 28 from which lubricant flows through the choke 29 to the pipe 30 leading to the control device 66, while if the pressure of the lubricant in the passage 28 exceeds a predetermined value the ball valve 33 is unseated to release lubricant from the passage 28 and thus reduce the pressure on the lubricant therein.

Lubricant under pressure supplied to the pipe 30 flows to the chamber 93 at the face of the piston 92 of the control device 66, and to the chamber 85 between the valve 82 and the plunger 83. The pressure of the lubricant supplied by the pump in varies in accordance with the speed at which the pump is operated, and on an increase in the speed of the compressor crank shaft 1 to a predetermined value, the pressure of the lubricant supplied by the pump ID to the pipe 39 exerts suflicient force on the piston 92. to the move the piston and the valve 95 against the coil spring 91, while the lubricant supplied to the chamber 85' moves the plunger 83 against the spring 86 away from the valve 82, and also exerts force on the valve 82 to press it'against the seat rib 84.

The valve 95 is moved by the piston 92 to cut 5uofl the supply of fluid under pressure from the passage I5 to the chamber 94 and to the pipe 64 leading to the compressor unloading means 52, and to open communication from the chamber 94 to the chamber 96 so that fluid under pressure is released from the compressor unloading means 52 to the atmosphere by way of the pipe 64, the chambers 94 and 95, passage and pipe 99 and the compressor crankcase chamber 5.

On this reduction'in the pressure of the fluid in the chamber 62 of the unloading means 52, the plunger 56 is moved upwardly by the spring 58 so that the stem 51 is moved away from the inlet valve 48 to permit the inlet valve to be moved to the seated position by the spring 49 to load the compressor.

On continued operation of the compressor, fluid is drawn into the compression chamber 4 from the atmosphere through the inlet passage 45 and chamber 44, and past the inlet valve 48 on the downward strokes of the piston 2, and on upward strokes of this piston, the inlet valve 48 is moved to the seated position by the spring 49, while the fluid in the compression chamber 4 is compressed past the exhaust valve 42 to the reservoir 40 to increase the pressure of the fluid therein.

When fluid is drawn into the inlet chamber 44 through the passage 45 there is a reduction in the pressure of the fluid in the inlet passage 45 and fluid flows to the inlet passage from the crankcase chamber 5 through the pipe 43, thereby reducing the pressure in the crankcase chamber 5 to a value somewhat below the pressure of the atmos phere. The ball check valve 9 operates at this time to prevent the flow of fluid from the atmosphere to the crankcase chamber 5 through the passage in the plug 9. As the crankcase chamber 5 is maintained at a pressure somewhat below atmosphere, fluid from the atmosphere tends to flow to the crankcase chamber through the joints in the casing sections of which the crankcase chamber is constructed and thereby tends to prevent leakage of lubricant from the crankcase chamber through these Joints.

As a result of operation of the compressor I there is an increase in the pressure of the fluid in the reservoir 40, and a corresponding increase in the pressure of the fluid in the chamber 14 at the face of the flexible diaphragm T of the control device 66. On an increase in the pressure of the fluid in the chamber 14 force is exerted through the diaphragm 10 to move the plunger 11 against the spring '18, and after a slight movement of this plunger against the spring, the end of the plunger engages a face of the disc valve 82 so that further movement of the plunger is resisted by the lubricant under pressure in the chamber 85 at the face of the disc valve 82. When the pressure of the fluid in the reservoir 40, and in the chamber 14, has increased to a predetermined relatively high value, the force exerted thereby is suflicient to overcome the opposing force of the spring 18 and of the lubricant under pressure operating against the disc valve 82, and the plunger 11 is thereupon moved to the right, as viewed in the drawing, and movesthe disc valve 82 away from the seat rib B4 to open a communication through which lubricant supplied to the chamber 85 by way of the passage 30 may escape at a rapid rate to the chamber 88, and thence by way of the passage and pipe 90 to the crank case chamber of the compressor.

As a result of the release of lubricant under pressure from the chamber 30 there is a rapid reduction in the pressure exerted thereon as lubricant is supplied to this passage only at a restricted rate by the pump I0 through the choke 29, and on this reduction in the pressure on the lubricant in the passage 30 there is a. corresponding reduction in the pressure on the lubricant in the chamber 93 at the face of the piston 92. The force exerted by the lubricant on the piston 92 will then be insufficient to maintain the piston and the valve 95 against the opposing force of the spring 91 with the result that the valve 95 and the piston 92 are moved to the right, as viewed in the drawing, by the spring 91. On this movement of the valve 95 communication between the chamber 94 and the chamber 96 is cut oil, while fluid under pressure flows from the passage 15 to the chamber 94, and thence by way of the pipe 64 to the chamber 62 of the compressor unloading means 52.

On an increase in the pressure of the fluid in the chamber 62 the plunger 56 is moved downwardly against the spring 58 to again unload the compressor as explained in detail above.

When the disc valve 82 of the control device 66 is moved away from the seat rib 84 and lubricant is released from the chamber 85 at the face of this disc valve, there is a reduction in the force 01 the fluid in the chamber ll, and in the reser-" voir ,isreducedtoavaiuesomewhatbelou' that required to initially move the plunger 11 against the combined forces of the spring II and or the lubricant operating on the valve II.

On the reduction in the pressure on the lubricant in the chamber II. the plunger II is moved,

bythespring IItopremthediscvalveIl against theendoithestemottheplunger II. The spring II is relatively weak, however, and the force exerted on the plunger TI is negligible in amount.

Atthistimeasthecompressorcontinuestobe operated, the lubricant pump II continues to exert pressure on the lubricant in the compressor lubricating system, while lubricant is supplied at a restricted rate through the choke 2! to the pipe II. However, as lubricant may escape from the passage 3| in the control device II, past the disc valve 82 at a much more rapid rate than lubricant is supplied through the choke 29, no pressurewillbedevelopedinthechamber "of the control device II, and the valve II will remain in the position to which it has been moved by the spring 91.

'Onareductioninthepressureoftheiiuidin the reservoir II to a predetermined relatively low value, the force exerted by fluid under pressureinthechamber llisinsuilicienttomaintain the plunger 11 against the opposing force of the spring 18, and the plunger I1 is thereupon moved to a position to permit the spring II, operating through the plunger II to move the disc valve 82 totheseatedpositlontocutoifthereleaseof lubricant from the chamber II tothe chamber II. On the continued supply of lubricantby the lubricantpump lltothepipelithereisanincrease inthepressureoithelubrlcanthithepipeand passageltandashnilarincreaseintbeprer sureoithelubricantintbechamberliattbe iaceoitbepiston ll,whiletorceisexertedby thislubricantonthediscvalvefltomsintsin itintheseatedpositionandtomovetheplunger 83 against the spring II.

On this increase in the pressure of the lubricant'in the chamber II, the piston I! is moved to the left, as viewed in the drawing, and moves the valve 95 against the spring II to out 0! the supply 0! fluid under presmre from the passage 'litothechamberflandthencetothecompressor unloading means II by way oi the pipe 6|,andtoreleasefluidfromthechamberllahd from the compressor unloading means II to again ellect loading of the compressor, as explained in detail above, so that on continued operation of the compressor, fluid is compressed into the reservoirlltoincreasethepressureosthefluid therein.

The control device II also operates to automatically mined the compressor when the compressor ceasestobeoperatemorintheeventoi' failure of the compressor lubricating system. Whenthecompressorisnolongeroperatedtbe lubricant pump I I does not supply lubricant under pressure to the pipe II, and, similarly, ii the lubricating system of the compressor fails to function properly, lubricant at the proper pressurewillnotbesuppliedtothepipell. Ona reduction in the pressure of the lubricant suppliedtothe pipe litoranyreasomthereisa corresponding reduction in the pressure oi the lubricantinthechamber atthefaceotthe piston I2, andtheiorceexertedbythislubricant on the piston i2 is insumcient to piston and the valve II against the opposing force or the spring II, which thereupon moves thevalveflltoapositiontocutoiicommimication between the chamber II and the chamber II, and to permit fluid under pressure supplied from the reservoir II to the passage II to how tothechamberfl,andthcncebywayoithe pipe tltotbeunloadingmeans I2 iorthecompressor to unload the compressor.

The lubricant supply system provided by this invention includes a supplementary lubricant reservoir III which, as shown, comprises a tubularshell Ill havingoneendclosedbymeansoi a head III.

The reservoir III may be located adiacent the compressor 1 or at a point spaced from the compressor, but is mounted vertically below the crankcase chamber I of the compressor. A pipe Ill communicates with the upper portion of the reservoir III and with the compressor crankcase chamber I substantially at the level at which it is desired to maintain the lubricant in the crankcasechamber, Iithelevelofthelubricantin the crankcase chamber rises above the desired level, lubricant will flow by gravity from the crankcase chamber I through the pipe "I to the reservoir I" to reduce the lubricant in the crankcase chamber I to the desired level.

'lheheadllihasafllleropeningformed therein and communicating with the upper portionoi'thereservoir Ill. Thisopeningisclosed by means of a threaded plug III having a chamberthereininwhichismounted aballvalve III whichisheld withinthechamberbymeansoia perforated retainer III. The ball valve III is adaptedtoseatuponaseatsurronmdmgapassage throughtheplug III andoperatestopermit fluid toescape from the'upperportion oithe reservoir III to the atmosphere and thereby preventabuildupoipressureinthereservoir,while theballvalve lilalsoservestopreventtheflow oiiiuidiromtheatmosphcretothereservoirlll, andthencebywayofthepipe llltothecompressor crankcase chamber I on a reduction in thepressureoithefluidinthecrankcasechambertoavaluebelowatmosphericpressure.

Thehead llihasassociated therewith supply meanslll for supplying lubricant irom the reservoir llltothecrankcasechamber I,and,as showmthismeanscomprlsesabodyillhaving a bore therein in which is mounted a hollow piston III having at one face a chamber 3 whichisconstantly connectedbywayofapipe III with the pipe II connecting the unloading control device II and the unloading means 52. The end of the bore in the body lll adjacent the chamber "3 is surrounded by a seat indicated at III and adapted at certain times, as willbereinaiter more fully appear,tobeengaged byacomplementaryseatlliiormedonthepiston 2 to prevent leakage of fluid from the chamber III through theboreinthebody Ill. The piston III has at the other face-thereof acbamberlllin'whichismountedacoilspring III, which extendsbetweenawallofthecham- ,ber I" andtheface oithepiston H2 andyieldingly urges thepisto'n III to the right, as viewed in Fig. 2 of the drawing, until a projection ill on the piston engages a wall oi the chamber ill to prevent further movement 0! the piston.

The chamber III is connected with the lower 76 portion of the reservoir I 00 by way of a passage I20, while a ball check valve I22 is provided and operates to permit the supply of lubricant from the reservoir to the chamber H8, and to prevent back flow of lubricant from the chamber II8 to the reservoir.

The body II I has formed therein a chamber I28 which is constantly connected by way of a pipe I25 with the crankcase chamber 5 of the compressor I. One side of the chamber I24 is closed by means of a threaded plug I28, while a ball check valve I30 is mounted in the chamber I24 and operates to permit lubricant to be supplied from the chamber I I8 to the chamber I28 and thence by way of the pipe I25 to the crankcase chamber 5, and to prevent back flow of lubricant from the crankcase chamber 5 and the pipe I20 to the chamber I I8.

In the operation of this lubricant supply system lubricant is initially supplied to the compressor crankcase chamber 5 and to thereservoir I00 to flll the crankcase chamber 5 to the desired level, and to flll the reservoir I00 substantially to the level permitted by the flller plug I06. If the level of the lubricant in the crankcase chamber 5 is raised too far, excess lubricant will flow from the crankcase chamber by way of the pipe I00 to the reservoir I00 to reatmosphere.

At this time, assuming that the compressor is idle, the control device 56 operates to supply fluid under pressure to the pipe 64 with the result that the chamber 62 of the compressor unloading means 52, and the chamber H3 of the lubricant supply means IIO are maintained substantially at reservoir pressure.

As the chamber 62 of the unloading means 52 is at reservoir pressure, the plunger 56 is maintained in the position in which the stem 21 holds the inlet valve 48 away from its seat against the spring 49 and thereby unloads the compressor I, as explained above.

As the chamber II3 of the lubricant supply means H0 is at atmospheric pressure the piston II2 is held against the spring I I9 in the position in which the seat I'IB thereon engages the seat II5 on the body III to prevent leakage of fluid from the chamber II3.

When the compressor crankshaft 'I is rotated, the piston 2 is reciprocated in the bore in which it is mounted and the fluid which is drawn into the compression chamber 4 on the downward strokes of the piston is forced out past the open inlet valve 48 on the upward strokes of the piston. In addition, upon rotation of the compressor crankshaft I, the lubricant pump I0 draws lubricant from the lower portion of the crankcase chamber 5 and supplies it under pressure to the portions of the compressor to be lubricated, and also supplies lubricant under pressure to the pipe 30 leading to the control device 66.

When the speed of the compressor has increased to a predetermined value, the pressure exerted by the lubricant pump I0 on the lubricant supplied thereby to the control device 86 is high enough to cause the piston 92 to be moved against the spring 97 so that the valve 05 is moved to a position to cut off the supply of fluid under pressure from the pipe, and passage I5 to the chamber 04, and thence to the pipe 64 leading to the compressor unloading means 52, and to the chamber II3 oi the lubricant supply means III], while the valve is moved to a position to release fluid irom the chamber 90. Upon the release of fluid from the chamber 98, fluid is released from the pipe Bfl'leading from the compressor unloading means 52 to thereby'load the compressor.

In addition, upon the release of fluid under pressure from the chamberjd, fluid is released from the chamber H8 of the lubricant supply means H0 and the, piston II2 thereof is moved by the spring II9 untfl the projection III on the piston engages a wall of the chamber I I3 to prevent further movement of the piston.

On this movement 01' the piston II 2 there is an increase in the volume of the chamber I I8 and lubricant is drawn into this chamber from the reservoir I00 through the passage I20 past the ball check valve I22.

. On the occurrence of a condition to which the control device 86 is adapted to respond to effect unloading of the compressor this device operates, as described in detail above, tocut off communication between the chamber 94 and the atmosphere, and to open communication from the passage I5 to the chamber so that fluid under pressure flows from the reservoir 40 to the pipe 08 leading to the compressor unloading means 52 to effect unloading of the compressor, while fluid under pressure supplied to the pipe 60 flows therefrom by way of the pipe H4 to the chamber II3 of the lubricant supply means IIO.

fluid from the chamber II 3. On this movement of the piston II2 force is exerted upon the lubricant contained in the chamber H8, and lubricant flows from this chamber past the ball check valve I30 to the chamber I24, and thence by way of the pipe I20 to the compressor crankcase chamber 5 to increase the supply of lubricant in y the crankcase chamber. On this movement of the piston II2, the ball check valve I22 prevents back flow of lubricant from the chamber II8 to the passage I20 leading to the reservoir I00.

On the occurrence of a condition to which the control device 66 is adapted to respond to effect loading of the compressor, this device operates to cut off the supply of fluid from the reservoir 40 to the pipe 64, and to release fluid from this pipe.

On the release of fluid under pressure from the pipe 64 fluid is released from the compressor unloading means 52 and this means operates, as described in detail above, to again effect loading of the compressor. In addition, upon the release of fluid under pressure from the pipe 64 fluid is released from the chamber II3 of the lubricant supply means I I 0, and on a reduction in the pressure of the fluid in the chamber II3, the piston II2 is again moved to the right, as viewed in the drawing, by the spring II9 until the projection III on the piston engages the wall of the chamber II3.

On this movement of the piston II2 there is a reduction in the pressure on the lubricant contained in the chamber 5 i8. At this time the ball check valve i30 is moved to the seated position to prevent back flow of lubricant from the chamber I24 to the chamber iii, and on a reduction in the pressure on the lubricant in the chamber H8 lubricant is drawn into this chamber past the ball check valve I22 from the'reservolr Ill.

the control device 88 to unload and load the compressor I.

The piston H2 0! the lubricant supply means H0 is proportioned so that the quantity of lubricant supplied by it to the compressor crankcase chamber 5 on each stroke of the piston is somewhat greater than is required to replace the inbricant consumed by the compressor during the usual or normal time intervals between operations of the control device 68 to unload the compressor.

As a result oi the oversupply of lubricant to the crankcase chamber, the lubricant therein will be increased to a level above that which it is desired to maintain in the compressor crankcase chamber. On this oversupply of lubricant to the crankcase chamber, excess lubricant will flow by gravity from the crankcase chamber 5 by way of the pipe I04 to the reservoir I00 to reduce the lubricant in the crankcase chamber to the desired level.

The lubricant supplied from thereservoir Ill to the crankcase chamber is relatively cool because of having been in the reservoir, while the lubricant which flows from the crankcase chamber to the reservoir is relatively hot because of its contact with the portions of the compressor which become heated during operation of the compressor. As some of the heated lubricant in the compressor crankcase chamber is periodically replaced by cool lubricant, the lubricant in the crankcase chamber will be maintained at a somewhat lower temperature than would be the case it cool lubricant were not supplied thereto. or it only sumcient lubricant were supplied to this chamber to replace that consumed during operation of the compressor.

The lubricant supplied from the crankcase chamber to the reservoir I00 will contain some dirt or foreign material which will settle out of the lubricant in the reservoir ill and collect on the bottom of this reservoir. The e Ill leading from the reservoir I" to the lubricant supply means Ill communicates with the reservoir Hill at a point somewhat above the lower wall thereof so that any dirt which collects in the bottom of the reservoir ill will not reach the passage I20 and interfere with the flow of lubricant to the lubricant supply means Ill, or be supplied along with lubricant to the crankcase chamber 5. This arrangement, therefore. servu to insure that the lubricant supply means will not be rendered inoperative, and it also serves to reduce the injurious foreign matter present in the lubricant in the crankcase chamber 5.

It will be seen that my invention provides .means to automatically maintain the lubricant supply in the crankcase chamber 01' a compressor pressor lubricating system provided by this invention has been illustrated and described in detail. it should be understood that the invention is not limited to these details of construction, and that numerous changes and modifications may be made without departing from the scope of the following claims. i

Having now described my invention, what I claim asnewanddeslretosecurebyLettersPatcut, is:

1. In combination, a fluid compressor having a crankcase chamber adapted to contain a quantity of lubricant and having an inlet passage through which fluid to be compressed is drawn from the atmosphere, a communication between said crankcase chamber and said inlet e, a communication through which fluid may be released from the crankcase chamber to the atmosphere, means to prevent flow oi fluid irom the atmosphere to the crankcase chamber through said communication, a supplementary lubricant reservoir, a communication through which lubricant may flow from the crankcase chamber to the supplementary lubricant reservoir on a predetermined increase in the level of the lubricant in the crankcase chamber, a communication through which fluid may be released from the upper portion of said reservoir to the atmosphere, and means to prevent flow oi fluid'i'rom the atmosphere to the reservoir through said commu-= nication.

2. The combination with a fluid compressor oiatypehavingalubricant chamberadaptedto contain a quantity of lubricant tor lubricating the compressor, unloading means responsive to the pressure of the fluid in a chamber, and means for eflecting the supply and release of fluid under pressure to and iron said chamber to condition the unloading means to effect loading and unloading oi the compressor, of a supplementary lubricant reservoir, and means responsive to the pressure of the fluid in said chamber for supplyin lubricant irom said supplementary reservoir to said lubricant chamber.

3. The combination with a fluid compressor of a type having a lubricant chamber adapted to contain a quantity of lubricant for lubricating the compressor. imloading means responsive to thepressureoi thefluidinapressurechambcr, and means for eflecting the supply and release 0! fluid under pressure to and irom said pressure chamber to condition the unloading means to effect loading and unloading of the compressor, of a supplementary lubricant reservoir, means responsive to the pressure of the fluid in said pressure chamber for supplying lubricant from said supplementary reservoir to said lubricant chamber, and a communication through which lubricant flows by gravity irom the lubricant chamber to the supplementary reservoir on a predetermined increase in the level of the lubricant in said lubricant chamber.

JOSEPH C. McCUNE. 

